3dB hybrid bridge design method and 3dB hybrid bridge

Abstract

The invention provides a 3d-B hybrid bridge design method. The 3d-B hybrid bridge design method comprises the following specific steps: S1, designing a 3d-B hybrid bridge according to a required performance index; s2, performing modeling and simulation analysis on the 3d B hybrid bridge to obtain a first simulation result; s3, judging whether a first simulation result meets performance index requirements or not, if not, performing principle analysis, and determining compensation types and values to be added to each port of the model; s4, optimizing and modifying the model according to a compensation type to be added and a numerical value to obtain a new-version model; and S5, carrying out simulation analysis on the new-version model again to obtain a second simulation result, and carrying out real object processing and manufacturing after confirming that the performance indexes are met. Modeling analysis is carried out on the 3d B hybrid bridge in the design stage, the principle of the 3d B hybrid bridge is analyzed when the performance index does not meet the requirement, compensation is increased, and the performance index of the bridge is improved.

Description

Technical Field

[0001] This application relates to the technical field of 3dB hybrid couplers, and particularly to a design method for 3dB hybrid couplers and a 3dB hybrid coupler. Background Art

[0002] As a common microwave / millimeter-wave device in modern communication systems, a 3dB hybrid coupler can divide an input signal into two signals with equal amplitude and a 90° phase difference, and is mainly used in multiplex signal synthesis to improve signal utilization. A 3dB hybrid coupler is a very commonly used device in passive devices. The main characteristics of a 3dB hybrid coupler are wide operating frequency band, low in-band insertion loss, high isolation, high return loss, and high amplitude balance and phase balance, which can meet the strict requirements of power distribution, synthesis, and signal control such as balanced amplifiers, variable attenuators, variable phase shifters, and low-noise amplifiers, and is easy to process. At present, the 3dB hybrid couplers designed by conventional design methods cannot meet the high-performance index requirements. For example, the overall value of the voltage standing wave ratio is relatively high, and the entire coupler shows obvious inductance, resulting in poor isolation of the 3dB hybrid coupler and inability to ensure product reliability. Summary of the Invention

[0003] To solve the above problems, this application provides a design method for a 3dB hybrid coupler. By modeling and analyzing the 3dB hybrid coupler in the design stage, when the performance index does not meet the requirements, its principle is analyzed and compensation is added to improve the performance index of the coupler.

[0004] To achieve the above object, the technical solution adopted in this application is as follows:

[0005] A design method for a 3dB hybrid coupler includes the following specific steps:

[0006] S1: Design a 3dB hybrid coupler according to the required performance index;

[0007] S2: Model and simulate the 3dB hybrid coupler to obtain the first simulation result;

[0008] S3: Determine whether the first simulation result meets the performance index requirements. If not, perform principle analysis to determine the type and value of compensation to be added to each port of the model;

[0009] S4: Optimize and modify the model according to the type and value of compensation to be added to obtain a new version of the model;

[0010] S5: Re-simulate the new version of the model to obtain the second simulation result. After confirming that the performance index is met, carry out physical processing and manufacturing.

[0011] Further, the performance indicators include center frequency, insertion loss, coupling degree, isolation degree, phase, and voltage standing wave ratio.

[0012] Further, the modeling and simulation analysis of the 3dB hybrid coupler are carried out using the electromagnetic simulation software HFSS.

[0013] Further, the principle analysis is carried out to determine the compensation type and value to be added to each port of the model, including the following steps:

[0014] Use ADS software to establish a principle simulation diagram and import the first simulation result;

[0015] Determine the compensation type for each port part of the principle simulation diagram;

[0016] Carry out fitting analysis and determine the compensation value;

[0017] According to the corresponding positions of the model and the principle simulation diagram, determine the compensation type and value to be added to each port of the model.

[0018] Further, the compensation type includes capacitive or inductive compensation.

[0019] Further, the optimization and modification of the model according to the compensation type and value to be added include the following steps:

[0020] When the compensation type is capacitive, calculate the size of the compensation block, the distance between the compensation block and each input terminal, and the dielectric type according to the compensation value;

[0021] Parallelly set compensation blocks at each input terminal of the model, and connect the compensation blocks and each input terminal through dielectric supports.

[0022] A 3dB hybrid coupler designed according to the 3dB hybrid coupler design method as described above.

[0023] Beneficial effects:

[0024] 1. By carrying out modeling analysis on the 3dB hybrid coupler in the design stage, analyzing its principle and adding compensation when the performance indicators do not meet the requirements, the performance indicators of the coupler are improved. Description of the drawings

[0025] Figure 1 It is a schematic flow diagram of a 3dB hybrid coupler design method;

[0026] Figure 2 It is a schematic plan view of the 3dB hybrid coupler before adding compensation;

[0027] Figure 3 It is a schematic three-dimensional view of the 3dB hybrid coupler before adding compensation;

[0028] Figure 4 Schematic diagram of the voltage standing wave ratio curve before adding compensation;

[0029] Figure 5 Schematic diagram of the Smith chart curve before adding compensation;

[0030] Figure 6 Schematic diagram of the isolation curve before adding compensation;

[0031] Figure 7 Principle simulation diagram before adding compensation;

[0032] Figure 8 Principle simulation diagram after adding compensation;

[0033] Figure 9 Schematic diagram of the planar structure of the 3dB hybrid coupler after adding compensation;

[0034] Figure 10 Schematic diagram of the three-dimensional structure of the 3dB hybrid coupler after adding compensation;

[0035] Figure 11 Schematic diagram of the voltage standing wave ratio curve after adding compensation;

[0036] Figure 12 Schematic diagram of the Smith chart curve after adding compensation;

[0037] Figure 13 Schematic diagram of the isolation curve after adding compensation.

[0038] Explanation of reference numerals: dielectric plate 1, first-layer signal conductor 2, via 3, second-layer signal conductor 4, capacitor conductor 5, terminal 6, conductor housing 7, dielectric plate 8, dielectric plate 9. Detailed implementation manners

[0039] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0040] The following describes the implementation manners of the present disclosure through specific examples. Those skilled in the art can easily understand other advantages and effects of the present disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts belong to the scope of protection of the present disclosure.

[0041] Embodiment 1

[0042] As Figure 1 shown is a schematic flow diagram of a 3dB hybrid coupler design method, including the following specific steps:

[0043] S1: Design a 3dB hybrid coupler according to the required performance indicators;

[0044] S2: Model and simulate the 3dB hybrid coupler to obtain the first simulation result;

[0045] S3: Determine whether the first simulation result meets the performance indicator requirements. If not, conduct a principle analysis to determine the compensation type and value to be added to each port of the model;

[0046] S4: Optimize and modify the model according to the compensation type and value to be added to obtain a new version of the model;

[0047] S5: Re - simulate the new version of the model to obtain the second simulation result. After confirming that it meets the performance indicators, conduct physical processing and manufacturing.

[0048] By modeling and analyzing the 3dB hybrid coupler in the design stage, when the performance indicators do not meet the requirements, conduct a principle analysis, add compensation, and improve the performance indicators of the coupler.

[0049] In this embodiment, design a 3dB hybrid coupler according to the required performance indicators proposed by the customer. The performance indicators include center frequency, insertion loss, coupling degree, isolation degree, phase, voltage standing - wave ratio, etc.; then, according to the designed dimensions, use HFSS software to model the 3dB hybrid coupler. The model structure is as Figure 2 、 Figure 3 shown. After building the model, conduct simulation analysis to obtain the first simulation result; the data generated by the first simulation result includes voltage standing - wave ratio, Smith chart, and isolation degree result files. The curve graphs generated by importing the result files into ADS software are as Figure 4 shown as the voltage standing - wave ratio curve, Figure 5 is the Smith chart curve, Figure 6 is the isolation degree curve. Among them, Figure 5 the bold curve in is the impedance line of the surrogate coupler. The closer the impedance line is to the middle resistive line, the better the performance of the coupler. However, this impedance line is in the inductive region, indicating that the coupler shows inductance and has poor performance. In Figure 4 the voltage standing - wave ratio curve also reflects the same. The closer the voltage standing - wave ratio curve is to 1, the better the performance of the coupler. However, at this time, the lowest point of the voltage standing - wave ratio curve is also higher than 1.2, indicating that the performance of the coupler is poor. Similarly, in Figure 6The isolation curve in [it] also shows the same response. Therefore, the conventional design makes the 3dB hybrid coupler unable to meet the requirements of high performance.

[0050] In specific implementation, the modeling and simulation analysis of the 3dB hybrid coupler are carried out using the electromagnetic simulation software HFSS. After obtaining the result data, it can be visually displayed in the form of a graphic curve by importing it into the ADS software.

[0051] In specific implementation, in the solution of this embodiment, after it is found that the 3dB hybrid coupler cannot meet the performance index, a principle analysis is carried out on the first simulation result of the model; for the said principle analysis to determine the compensation type and value to be added to each port of the model, the following steps are included:

[0052] Use the ADS software to establish a principle simulation diagram as shown in Figure 7 and import the first simulation result. The first simulation result is like the square result in the middle (labeled SNP1 with letters); Figure 7

[0053] Determine the compensation type for each port part of the principle simulation diagram. The first simulation result shows inductance, so a capacitance compensation is added in this embodiment; through the odd - even mode theory analysis, when the product of the odd - mode impedance Zoo and the even - mode impedance Zoe is equal to the square of the characteristic impedance Zo (as shown in Formula 1), the performance of the coupler is completely matched, without mismatch, and the performance of the coupler fully meets the design requirements:

[0054] Zoo * Zoe = Zo^2 (Formula 1)

[0055] Through Figure 5 it is known that when there is no compensation block in the coupler, the coupler impedance is in the inductive region, in a mismatched state, and the isolation of the coupler is poor. A capacitance compensation block needs to be added to make it in a matched state, and the product of the odd - even mode impedance is equal to the square of the characteristic impedance. The Smith chart line is as close as possible to the resistive line. Therefore, a capacitance compensation block is added;

[0056] Carry out fitting analysis and determine the compensation value. As shown in Figure 8 is the principle simulation diagram after adding capacitance compensation. The compensation capacitors are capacitor C1, capacitor C2, capacitor C3, and capacitor C4;

[0057] According to the corresponding positions of the model and the principle simulation diagram, determine the compensation type and value to be added to each port of the model, that is, determine the capacitors and their capacitance values added to each port of the model according to the principle simulation diagram after adding compensation, and adjust the model parameters to make the performance of the 3dB hybrid coupler reach the optimal value.

[0058] ​Then, optimize and modify the model according to the compensation type and value to be added, including the following steps: When the compensation type is capacitive, calculate the size of the compensation block, the distance between the compensation block and each input terminal, and the dielectric type according to the compensation value; Parallelly set the compensation blocks at each input terminal of the model according to the calculated distance, and connect the compensation blocks and each input terminal through dielectric supports. The model after adding the compensation blocks is as Figure 9 and Figure 10 shown.

[0059] Finally, re - perform simulation analysis on the new version of the model after adding the compensation blocks to obtain the second simulation result. The data generated by the second simulation result also includes the voltage standing wave ratio, Smith chart, and isolation degree result files, and the curve graphs generated by importing the result files into the ADS software. As Figure 11 shown is the voltage standing wave ratio curve after adding the compensation blocks, Figure 12 is the Smith chart curve after adding the compensation blocks, Figure 13 is the isolation degree curve after adding the compensation blocks. Among them, Figure 12 the impedance line in Figure 5 is closer to the middle resistive line than that in Figure 11 , indicating better performance of the bridge. This is also reflected in the voltage standing wave ratio curve in Figure 4 , and the voltage standing wave ratio curve is closer to 1 than that in Figure 13 . The isolation degree curve of

[0060] also shows the same. Therefore, the 3dB hybrid bridge after adding the capacitive compensation block can meet the requirements of high performance.

[0061] Through the odd - even mode theory analysis, when the product of the odd - mode impedance Zoo and the even - mode impedance Zoe is equal to the square of the characteristic impedance Zo, the performance of the bridge is completely matched without mismatch, and the performance of the bridge fully meets the design requirements. Figure 9 It is known through

[0062] that since the bridge is a four - port reciprocal symmetric device, the sizes of the compensation blocks added to the four ports are the same. In the design frequency band, when there are compensation blocks in the bridge, the overall impedance of the bridge is near the resistive line and in a matching state, and the product of the odd - and even - mode impedances is equal to the square of the characteristic impedance. Therefore, adding the capacitive compensation block makes the performance of the bridge in a matching state, and the isolation degree, coupling degree, and through - put of the bridge all meet the design requirements.

[0063] Embodiment 2

[0064] A 3dB hybrid bridge designed according to the 3dB hybrid bridge design method described above, and the 3dB hybrid bridge is as Figure 9 、 Figure 10As shown in the figure, it includes a conductor housing 7; terminal blocks 6 are respectively provided at the four corners of the conductor housing 7; an insulating medium is provided between the terminal blocks 6 and the conductor housing 7 to prevent conduction; inside the conductor housing 7, a first-layer signal conductor 2 and a second-layer signal conductor 4 are stacked up and down; a dielectric plate 1 is provided between the first-layer signal conductor 2 and the second-layer signal conductor 4; dielectric plates 8 are also provided between the first-layer signal conductor 2 and the adjacent conductor housing 7 and terminal blocks 6; dielectric plates 9 are also provided between the second-layer signal conductor 4 and the adjacent conductor housing 7 and terminal blocks 6; both ends of the first-layer signal conductor 2 are connected to the terminal blocks 6 at the lower left corner and the upper right corner through vias 3, and a metal layer is provided inside the vias 3 to conduct both ends of the first-layer signal conductor 2 and the terminal blocks 6; both ends of the second-layer signal conductor 4 are connected to the terminal blocks 6 at the upper left corner and the lower right corner through vias 3, and a metal layer is provided inside the vias 3 to conduct both ends of the second-layer signal conductor 4 and the terminal blocks 6, so that the external circuit can be connected to the internal first-layer signal conductor 2 and second-layer signal conductor 4 only by connecting to the terminal blocks 6; capacitor conductors 5 are provided at positions corresponding to both ends of the first-layer signal conductor 2 in the dielectric plate 8, and similarly, capacitor conductors 5 are also provided at positions corresponding to both ends of the second-layer signal conductor 4 in the dielectric plate 9; the vias 3 at the corresponding positions of each end pass through the capacitor conductors 5 corresponding to that end, but an insulating medium is provided between the metal layer in the vias 3 and the capacitor conductors 5 to prevent conduction, so that the capacitor conductors 5 become capacitor compensation blocks. The capacitor conductors 5 become capacitor compensation blocks at the ends of the adjacent signal conductors. Compared with the case without capacitor compensation blocks, the advantages of this solution are as follows: The voltage standing wave ratio is improved, making the impedance line of the hybrid coupler closer to the resistive line, improving the isolation of the 3dB hybrid coupler. The conductors in this solution use copper conductors, and due to the increased copper conductor area, its heat dissipation capacity and power capacity have also been improved.

[0065] The present application provides a flow schematic diagram of a 3dB hybrid coupler design method, including the following specific steps:

[0066] S1: Design a 3dB hybrid coupler according to the required performance indicators; S2: Model and simulate the 3dB hybrid coupler to obtain the first simulation result; S3: Determine whether the first simulation result meets the requirements of the performance indicators. If not, conduct a principle analysis to determine the compensation type and value to be added to each port of the model; S4: Optimize and modify the model according to the compensation type and value to be added to obtain a new version of the model; S5: Re-simulate and analyze the new version of the model to obtain the second simulation result. After confirming that the performance indicators are met, conduct physical processing and manufacturing. By modeling and analyzing the 3dB hybrid coupler in the design stage, when the performance indicators do not meet the requirements, analyze its principle and add compensation to improve the performance indicators of the coupler. Aiming at the problem that the voltage standing wave ratio difference of the 3dB hybrid coupler causes deterioration of both isolation and coupling, this application provides a method of adding a capacitance compensation block in the coupler to optimize the voltage standing wave ratio, explores the relationship between the capacitance compensation block and the voltage standing wave ratio, and analyzes the reason for the deterioration of the voltage standing wave ratio of the 3dB hybrid coupler from the root cause. The method is more universal; for the voltage standing wave ratio optimization method of the 3dB hybrid coupler proposed in this application, when the dielectric constant and thickness of the material are determined, compare the voltage standing wave ratio of the 3dB hybrid coupler with and without the capacitance compensation block, and comparative analysis can be carried out at the initial stage of design, effectively improving the product qualification rate; compared with the case without the capacitance compensation block, the advantages of this application are as follows: the voltage standing wave ratio is improved, the isolation of the 3dB hybrid coupler is increased, and due to the increase in the copper conductor area, its heat dissipation capacity and power capacity are both improved.

[0067] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "middle", "length", "upper", "lower", "front", "rear", "vertical", "horizontal", "inner", "outer", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0068] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. The meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically limited.

[0069] In the present invention, unless otherwise clearly defined or limited, terms such as "installed", "connected", "linked", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] The above is only to illustrate the embodiments of the present invention and is not intended to limit the present invention. For those skilled in the art, any modifications, equivalent replacements, improvements, etc. made without creative efforts within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A 3dB hybrid coupler design method, characterized in that It includes the following specific steps: S1: Design a 3dB hybrid coupler according to the required performance indicators; S2: Model and simulate the 3dB hybrid coupler to obtain the first simulation result; S3: Determine whether the first simulation result meets the requirements of the performance indicators. If not, conduct a principle analysis to determine the compensation type and value to be added to each port of the model; S4: Optimize and modify the model according to the compensation type and value to be added to obtain a new version of the model; S5: Re-simulate and analyze the new version of the model to obtain the second simulation result. After confirming that it meets the performance indicators, conduct physical processing and manufacturing.

2. The 3D B hybrid bridge design method according to claim 1, wherein The performance indicators include center frequency, insertion loss, coupling degree, isolation degree, phase, and voltage standing wave ratio.

3. The 3D B hybrid bridge design method according to claim 1, characterized in that The modeling and simulation analysis of the 3dB hybrid coupler are carried out using the electromagnetic simulation software HFSS.

4. The 3D B hybrid bridge design method according to claim 1, wherein The principle analysis to determine the compensation type and value to be added to each port of the model includes the following steps: Use ADS software to establish a principle simulation diagram and import the first simulation result; Determine the compensation type for each port part of the principle simulation diagram; Conduct a fitting analysis and determine the compensation value; According to the corresponding positions of the model and the principle simulation diagram, determine the compensation type and value to be added to each port of the model.

5. The 3D B hybrid bridge design method according to claim 4, characterized in that The compensation type includes capacitive or inductive compensation.

6. The 3D B hybrid bridge design method according to claim 5, characterized in that, The optimization and modification of the model according to the compensation type and value to be added include the following steps: When the compensation type is capacitive, calculate the size of the compensation block, the distance between the compensation block and each input terminal, and the dielectric type according to the compensation value; Parallelly set compensation blocks at each input terminal of the model, and connect the compensation blocks and each input terminal through dielectric supports.

7. A 3D B hybrid bridge, characterized in that, It is designed according to the 3dB hybrid coupler design method described in any one of claims 1 to 6.

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